The Seattle Art Museum announced yesterday that it is returning a $2 million painting by Henri Matisse to the heirs of Paul Rosenberg, a prominent Jewish art dealer in Paris whose collection was confiscated by the Nazis during World War II.

The decision to give the painting, "Odalisque" (1928), to the Rosenberg heirs is a first for an American art museum. Millions of dollars have been spent in recent years litigating the ownership of art taken from Holocaust victims.

In a statement issued at a press conference here yesterday, SAM director Mimi Gardner Gates said the decision had been made after an investigation by Washington's Holocaust Art Restitution Project (HARP) showed that the painting had indeed been stolen from Rosenberg's storage vault. The Matisse came to the museum as a gift from Seattle lumber barons Virginia and Prentice Bloedel, who purchased it in 1954 from Knoedler & Co., a New York art dealer.

"By our action, the museum is drawing a clear ethical line," Gardner said. "Since day one, SAM has been committed to doing the right thing." The museum even footed the $10,000 cost of the HARP research.

In an even more remarkable case this month, the National Gallery of Berlin announced that it would return a van Gogh drawing with an estimated value of more than $5 million to the only surviving heir of the German collector Max Silberberg, who was forced to sell off more than 150 paintings and drawings in the 1930s before he and his wife were sent to Auschwitz. The painting will be returned to his 85-year-old daughter-in-law, who lives in England.

The Silberberg case is important not only because it sets a precedent for other German museums but because, for the first time, it recognizes the immorality--if not the illegality--of these "Jew auctions," as they were called in Nazi Germany. The sales took place by the dozens after 1933, when Jews were systematically forbidden to work and therefore forced to sell off their personal assets.

The decision was made on moral grounds, according to Prof. Klaus-Dieter Lehmann, president of the Foundation for Prussian Cultural Heritage, the umbrella organization for Berlin's museums.

Two paintings from the Silberberg collection are now in the National Gallery of Art here in Washington: Renoir's "Girl With Hoop" and Gustave Courbet's "A Young Woman Reading." The gallery says that both were purchased by the great American collector Chester Dale at a Silberberg auction in Paris in 1932, before the Nazis took power, and were later given to the National Gallery.

Lawyers have not yet been entirely eliminated from the Seattle case. Last August, in the face of the ongoing investigation, the Seattle museum sued Knoedler & Co., claiming that the gallery committed fraud, negligent misrepresentation and breach of warranty of title in selling the Matisse to the Bloedels. It has asked for compensation of $2 million, the painting's fair market value at the time.

The details of how the painting got to Knoedler after World War II were part of the HARP report but were expunged from the version released yesterday.

CAPTION: Matisse's "Odalisque" was taken by the Nazis in 1941.